In recent years, liquid crystal display devices (LCDs), organic light emitting devices (OLEDs), or others, have been used for various purposes. Even many displays to be used outdoors make use of LCDs.
Further, LCDs have widely been used for dashboard panels, such as of vehicles, ships, or airplanes; car-mounted navigation systems; digital cameras; mobile devices such as mobile phones or personal computers; or digital signage to be used in, for example, buildings or supermarkets.
In such electronic equipment, there have widely been used touch sensors, each serving as a display and an input means.
Touch panels ordinarily used are of the optical type, ultrasonic type, electromagnetic induction type, resistive film type, or capacitive type. Touch panels of the resistive film type have often been combined with small liquid crystal displays. Touch panels of the resistive film type have a function as an input switch using transparent conductive films as conductors and having a structure that two transparent conductive films are opposed via a spacer. When they are pressed with a stylus or a finger, electrode surfaces mutually contact each other to cause electrical conduction, making possible the detection of its pressed position.
In contrast, touch panels of the capacitive type enable the detection of multiple points, what is called multi-touch, which cannot be achieved by those of the ordinary resistive film type, and therefore, capacitive touch panels have recently been attracting much attention.
Examples of the capacitive touch panel are disclosed in Patent Documents 1 and 2. These touch panels each comprises an X-electrode film having first island electrodes arranged in the X-axis direction and a first bridge wiring film electrically connecting the adjacent first island electrodes; and a Y-electrode film having second island electrodes arranged in the Y-axis direction perpendicular to the X-axis direction and a second bridge wiring film electrically connecting the adjacent second island electrodes. The first bridge wiring film and the second bridge wiring film are insulated from each other by an insulating film.
Another example of the capacitive touch panel is disclosed in Patent Document 3. In the capacitive touch panel of Patent Document 3, second electrodes arranged in the Y-axis direction are provided over conductive portions of first electrodes arranged in the X-axis direction. The second electrodes and the conductive portions are insulated from each other by an intermediate insulating layer.